Parent application Ser. No. 728,243; filed Sept. 30, 1976, discloses an instrument housing which incorporates various internal features for affording versatility to the housing. The general structure of the housing includes a top cover comprising a top wall with downwardly turned flanges and a similarly shaped bottom cover having flanges and with an H-shaped expander which fits over the flanges. The parent application also discloses a novel handle structure which likewise enhances the versatility of the housing.